Gas pressure regulators are used to provide a substantially continuous supply of gas at a substantially constant selected pressure to a gas outlet upon receiving pressurised gas from a gas source via a gas inlet. Gas pressure regulators are well known, and typically aim to down regulate high pressure gas received from a gas source, such as a loose standing gas cylinder, to a low pressure selected working gas pressure. Regulators typically comprise a gas inlet stem to receive the gas from the source, a regulating means to down regulate the inlet pressure to the desired pressure, and a gas outlet stem to dispense the down regulated gas at the selected desired pressure.
The down regulating means typically comprises a combination of a selecting means for selecting and setting the threshold pressure, and a restricting means for preventing gas exceeding the desired pressure from passing through the regulator from the gas inlet stem to the gas outlet stem. The selecting means and the restricting means typically act in concert in order to achieve the desired gas regulation. Typically, the selecting means includes an adjustable screw received through a housing of the gas regulator which in use actuates against a diaphragm located in an inside chamber of the housing allowing a user to adjust the volume of the chamber. Gas entry from the gas inlet stem into the chamber is controlled via the restricting means, typically a poppet valve. In use, gas enters the inlet stem and enters the chamber via the poppet valve. Should the gas exceed the predetermined threshold the pressure of the gas will close the poppet valve, thus preventing further gas from entering the chamber. The gas inside the chamber can exit through the outlet stem and/or purge valves. As the pressure exerted by the gas inside the chamber drops, the poppet valve opens allowing more gas into the chamber.
Gas regulators can be classified into single-stage and multi-stage regulators. Single stage regulators have a single chamber where regulation of gas pressure takes place, in contrast to multi-stage regulators, which have two or more chambers where regulation of gas pressure takes place.
There are several problems associated with known gas pressure regulators. The diaphragm used in conventional gas regulators is highly specialized, both in regard to its design and material composition. In addition, existing restricting means, such as poppet valves, are difficult to control smoothly so as to operate in a controlled manner.
There is thus a need to provide an encapsulated valve for use in gas pressure regulators and medical equipment that at least partially ameliorates some of the abovementioned problems.